2014 11 24

[Update: This will be a regular feature in V2.2, not an “advanced” feature]

Double (or multiple) star systems are not static. The primary and secondary stars typically move with respect to each other. These relative movements can be extremely small (i.e. they don’t appear to move over a period of decades or longer), or they might move relatively rapidly (with noticeable relative motion over a period of months or years). The double star catalogues, and in particular the Washington Double Star (WDS) catalogue, typically only show a single instance or snapshot of relative position (separation and position angle) for each object, which might be quite out-of-date (some even 100+ years out of date).

Many such star systems have been observed and the relative positions of the stars noted over an extended period, allowing the actual orbits of the stars to be estimated. A new feature in the Advanced version of AstroPlanner allows you to see those orbits and estimate the current relative positions of the stars.

2013 08 19

I have been pondering having an “Advanced” version of AstroPlanner containing various features only of interest to more advanced users. There would be an extra fee for these features to be enabled. Here’s some of my thinking on the matter.

2013 08 18

On the CN DSO forum is a rule of thumb for splitting double stars in discussion: Multiply delta-m (if less than 1 then set 1) with the Dawes limit of your scope to get the minimum separation you need to split this double star under otherwise excellent conditions (seeing etc.).

This rule would be nice if available as wizard or better as option when searching double star catalogues.

This seemed like a perfectly useful and easy-to-implement way of rejecting double stars that will not be splittable through a particular telescope, even under perfect conditions. So I decided to integrate it into V2.1.

2012 09 01

I have been asked on several occasions about the image quality setting in Image Preferences, and what effects it will have. To make things a bit clearer I have implemented a feature in V2.1 that compares the effect of saving DSS images at less than 100% quality. The results are quite revealing, even for me.

2012 07 17

A frequently-requested AstroPlanner feature is some kind of indication as to when the best time to observe a particular object would be. This would take into account many values, such as the altitude of the object, the phase of the moon, whether the moon is up, and how far from the moon the object is, etc. Enter the Observability value for an object.

2012 06 18

If you look at the object list in AstroPlanner, you will see a whole bunch of properties associated with those objects. Some of those properties remain constant over time (for non-solar-system objects, e.g. Magnitudes, RA/Dec coordinates, etc.), while other properties vary with the passage of time (e.g. Altitude, hour angle, parallactic angle, etc.).

It’s difficult to see how these latter properties change over, say, the course of an observing session. For some purposes, especially if you’re an astroimager, it’s important to know what those changes are. Enter a new feature to help with this kind of visualisation.